"We stand corrected on finding the wreckage because what we identified is not a part of our plane. So the search and rescue is still going on," Adel told CNN's "The Lead with Jake Tapper."

Adel said EgyptAir is not involved in the search and is getting its information from Greek authorities and the Egyptian military, but he didn't give details on why the debris found in the water was said to be from the plane or how that information was gathered.

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The plane was carrying 56 passengers and 10 crew and security officers.

Earlier, a spokesman for Greece's Hellenic National Defense general staff had said an Egyptian search aircraft spotted two floating objects 210 nautical miles southeast of Crete. It's unclear whether those objects were part of the wreckage described by Adel.

Speculation has centered on the possibility of a terrorist attack.

"It's very difficult to come up with a scenario that jibes with some sort of catastrophic failure. (The evidence so far) leads us down the road to a deliberate act," CNN aviation analyst Miles O'Brien said.

Latest developments

-- The pilots have been identified to CNN as Mohamed Said Shoukair and Mohamed Mamdouh Ahmed Assem, according to an official close to the investigation and a security source. The sources said Shoukair was the captain and Assem was the first officer. The head flight attendant was identified as Mirvat Zaharia Zaki Mohamed.

-- Maintenance checks on the plane had been done on time and "no snags were reported," Adel told Amanpour.

-- Checks of the passenger manifest have so far resulted in no hits on terror watch lists, officials with knowledge of the investigation told CNN.

-- U.S. government officials are operating on an initial theory that the plane was taken down by a bomb, two U.S. officials told CNN. Officials said the theory could change, with one senior administration official cautioning it is not yet supported by a "smoking gun."

-- The airplane "swerved and then plunged" before descending into the Mediterranean, Greek Defense Minister Panos Kammenos told reporters.

-- Greek controllers tried to reach EgyptAir Flight 804 about 10 miles before it left the country's airspace and for about 90 seconds after and received no response, the head of the Hellenic Civil Aviation Authority told Greek broadcaster ANT1 TV.

What happened

Photos:Search underway in EgyptAir MS804 crash

Photos:Search underway in EgyptAir MS804 crash

Egyptian armed forces release video and images of debris, including personal belongings, believed to be from EgyptAir Flight 804 on Saturday, May 21. The Airbus A320 vanished from radar over the Mediterranean Sea while en route from Paris to Cairo on Thursday, May 19, with 66 people aboard.

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Photos:Search underway in EgyptAir MS804 crash

At least one piece of debris has an EgyptAir logo.

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Photos:Search underway in EgyptAir MS804 crash

An uninflated life vest is among the debris recovered from the Mediterranean.

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Photos:Search underway in EgyptAir MS804 crash

Debris from EgyptAir flight 804.

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Photos:Search underway in EgyptAir MS804 crash

A piece of the wreckage from EgyptAir flight 804 is seen.

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Photos:Search underway in EgyptAir MS804 crash

Samir Abdel Bary, imam of Cairo's al Thawrah Mosque, consoles Tarek Abu Laban, who had four relatives on the flight, on Friday, May 20.

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Photos:Search underway in EgyptAir MS804 crash

A relative of a passenger who was on the jet waits for news at Cairo International Airport on May 19.

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Photos:Search underway in EgyptAir MS804 crash

Relatives of passengers comfort each other at Cairo International Airport on May 19.

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Photos:Search underway in EgyptAir MS804 crash

Relatives outside the crisis center at Cairo International Airport in Egypt.

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Photos:Search underway in EgyptAir MS804 crash

The EgyptAir in-flight service building in Cairo has been turned into a crisis center. Families have been provided with doctors and translators, the airline said.

At 2:27 a.m., shortly before the aircraft was scheduled to exit Greek airspace, controllers tried to reach the pilots to transfer control to Cairo authorities. Despite repeated attempts, they received no response, the Hellenic Civil Aviation Authority said.

Radar soon lost the plane's signal, just after it entered Egyptian airspace, the authority said.

At some point before dropping off radar, the plane swerved 90 degrees to the left, and then made a 360-degree turn to the right before plunging first to 15,000 feet, then 10,000 feet, Kammenos, the Greek defense minister, told reporters.

Weather conditions were clear at the time, CNN meteorologist Pedram Javaheri said.

More about the flight

The flight left Charles de Gaulle Airport in Paris at 11:09 p.m. Wednesday for what should have been about a 3½-hour flight.

The passengers were predominantly Egyptian -- 30 in all -- but also aboard were 15 French citizens, including an infant; two Iraqis; and one from each of the following: Britain, Belgium, Kuwait, Saudi Arabia, Sudan, Chad, Portugal, Algeria and Canada, according to Fathi, the Egyptian aviation minister.

The government of Canada said two of its citizens were on the plane. The reason for the discrepancy wasn't clear.

Australian Foreign Minister Julie Bishop said the British passenger also was an Australian citizen. It is unclear whether any other passengers were dual citizens.

The Airbus A320 had routine maintenance checks in Cairo before it left for Paris, an airline official said. Earlier Wednesday, the jet was also in Eritrea and Tunisia, data from flight tracking websites show.

There was no special cargo on the flight and no notification of any dangerous goods aboard, according to Adel of EgyptAir.

The plane has been part of EgyptAir's fleet since November 2003, according to Adel. It had about 48,000 flight hours. The plane's captain had about 6,000 flying hours, he said.

A distress signal was detected at 4:26 a.m. -- about two hours after the jet vanished -- in the general vicinity where it disappeared, Adel said. He said the distress signal could have come from another vessel in the Mediterranean. Egyptian armed forces said they had not received a distress call.

The search

The area being searched is about 130 nautical miles south-southeast of Karpathos, the Greek Hellenic National Defense General Staff said.

The Greek military was sending two aircraft, two helicopters and a frigate to the area where the plane was last seen on radar. The U.S. Navy deployed a P-3 Orion aircraft to assist in the search. Egypt's military was also involved, and France said it had tasked a surveillance plane to help.

They were taken to special centers at both airports, where translators and psychiatric support awaited. In Cairo's airport, dozens of relatives paced anxiously in a building set aside for families. Some shouted at photographers taking pictures of them, while others berated officials over the perceived lack of information.

Analysts weigh in

CNN aviation correspondent Richard Quest: "Planes just do not fall out of the sky for no reason, particularly at 37,000 feet," he said, noting the aircraft vanished while cruising -- the safest part of the journey.

David Soucie, a CNN aviation safety analyst: The first priority is to find survivors. "Find the plane, find the people, see if there are folks that could be rescued," he said. "Safety people are looking at safety issues, maintenance people looking at maintenance issues, security people looking at security issues."

CNN aviation analyst Les Abend: He said there are three possibilities: an explosion, something nefarious or a stall situation. "We're in the very early stages of the investigation. Any good accident investigator will tell you, just put on the brakes a little bit and let this thing unfold. The 360-degree turn, that seems very abrupt. It's not something I would do in any major emergency unless I was losing control of the aircraft," he said.